]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * mm/mprotect.c | |
3 | * | |
4 | * (C) Copyright 1994 Linus Torvalds | |
5 | * (C) Copyright 2002 Christoph Hellwig | |
6 | * | |
046c6884 | 7 | * Address space accounting code <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
8 | * (C) Copyright 2002 Red Hat Inc, All Rights Reserved |
9 | */ | |
10 | ||
11 | #include <linux/mm.h> | |
12 | #include <linux/hugetlb.h> | |
1da177e4 LT |
13 | #include <linux/shm.h> |
14 | #include <linux/mman.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/highmem.h> | |
17 | #include <linux/security.h> | |
18 | #include <linux/mempolicy.h> | |
19 | #include <linux/personality.h> | |
20 | #include <linux/syscalls.h> | |
0697212a CL |
21 | #include <linux/swap.h> |
22 | #include <linux/swapops.h> | |
cddb8a5c | 23 | #include <linux/mmu_notifier.h> |
64cdd548 | 24 | #include <linux/migrate.h> |
cdd6c482 | 25 | #include <linux/perf_event.h> |
e8c24d3a | 26 | #include <linux/pkeys.h> |
64a9a34e | 27 | #include <linux/ksm.h> |
7c0f6ba6 | 28 | #include <linux/uaccess.h> |
1da177e4 LT |
29 | #include <asm/pgtable.h> |
30 | #include <asm/cacheflush.h> | |
e8c24d3a | 31 | #include <asm/mmu_context.h> |
1da177e4 LT |
32 | #include <asm/tlbflush.h> |
33 | ||
36f88188 KS |
34 | #include "internal.h" |
35 | ||
4b10e7d5 | 36 | static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, |
c1e6098b | 37 | unsigned long addr, unsigned long end, pgprot_t newprot, |
0f19c179 | 38 | int dirty_accountable, int prot_numa) |
1da177e4 | 39 | { |
4b10e7d5 | 40 | struct mm_struct *mm = vma->vm_mm; |
0697212a | 41 | pte_t *pte, oldpte; |
705e87c0 | 42 | spinlock_t *ptl; |
7da4d641 | 43 | unsigned long pages = 0; |
3e321587 | 44 | int target_node = NUMA_NO_NODE; |
1da177e4 | 45 | |
175ad4f1 AA |
46 | /* |
47 | * Can be called with only the mmap_sem for reading by | |
48 | * prot_numa so we must check the pmd isn't constantly | |
49 | * changing from under us from pmd_none to pmd_trans_huge | |
50 | * and/or the other way around. | |
51 | */ | |
52 | if (pmd_trans_unstable(pmd)) | |
53 | return 0; | |
54 | ||
55 | /* | |
56 | * The pmd points to a regular pte so the pmd can't change | |
57 | * from under us even if the mmap_sem is only hold for | |
58 | * reading. | |
59 | */ | |
60 | pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); | |
1ad9f620 | 61 | |
3e321587 AK |
62 | /* Get target node for single threaded private VMAs */ |
63 | if (prot_numa && !(vma->vm_flags & VM_SHARED) && | |
64 | atomic_read(&vma->vm_mm->mm_users) == 1) | |
65 | target_node = numa_node_id(); | |
66 | ||
3ea27719 | 67 | flush_tlb_batched_pending(vma->vm_mm); |
6606c3e0 | 68 | arch_enter_lazy_mmu_mode(); |
1da177e4 | 69 | do { |
0697212a CL |
70 | oldpte = *pte; |
71 | if (pte_present(oldpte)) { | |
1da177e4 | 72 | pte_t ptent; |
b191f9b1 | 73 | bool preserve_write = prot_numa && pte_write(oldpte); |
1da177e4 | 74 | |
e944fd67 MG |
75 | /* |
76 | * Avoid trapping faults against the zero or KSM | |
77 | * pages. See similar comment in change_huge_pmd. | |
78 | */ | |
79 | if (prot_numa) { | |
80 | struct page *page; | |
81 | ||
82 | page = vm_normal_page(vma, addr, oldpte); | |
83 | if (!page || PageKsm(page)) | |
84 | continue; | |
10c1045f MG |
85 | |
86 | /* Avoid TLB flush if possible */ | |
87 | if (pte_protnone(oldpte)) | |
88 | continue; | |
3e321587 AK |
89 | |
90 | /* | |
91 | * Don't mess with PTEs if page is already on the node | |
92 | * a single-threaded process is running on. | |
93 | */ | |
94 | if (target_node == page_to_nid(page)) | |
95 | continue; | |
e944fd67 MG |
96 | } |
97 | ||
8a0516ed MG |
98 | ptent = ptep_modify_prot_start(mm, addr, pte); |
99 | ptent = pte_modify(ptent, newprot); | |
b191f9b1 | 100 | if (preserve_write) |
288bc549 | 101 | ptent = pte_mk_savedwrite(ptent); |
4b10e7d5 | 102 | |
8a0516ed MG |
103 | /* Avoid taking write faults for known dirty pages */ |
104 | if (dirty_accountable && pte_dirty(ptent) && | |
105 | (pte_soft_dirty(ptent) || | |
106 | !(vma->vm_flags & VM_SOFTDIRTY))) { | |
107 | ptent = pte_mkwrite(ptent); | |
4b10e7d5 | 108 | } |
8a0516ed MG |
109 | ptep_modify_prot_commit(mm, addr, pte, ptent); |
110 | pages++; | |
0661a336 | 111 | } else if (IS_ENABLED(CONFIG_MIGRATION)) { |
0697212a CL |
112 | swp_entry_t entry = pte_to_swp_entry(oldpte); |
113 | ||
114 | if (is_write_migration_entry(entry)) { | |
c3d16e16 | 115 | pte_t newpte; |
0697212a CL |
116 | /* |
117 | * A protection check is difficult so | |
118 | * just be safe and disable write | |
119 | */ | |
120 | make_migration_entry_read(&entry); | |
c3d16e16 CG |
121 | newpte = swp_entry_to_pte(entry); |
122 | if (pte_swp_soft_dirty(oldpte)) | |
123 | newpte = pte_swp_mksoft_dirty(newpte); | |
124 | set_pte_at(mm, addr, pte, newpte); | |
e920e14c MG |
125 | |
126 | pages++; | |
0697212a | 127 | } |
5042db43 JG |
128 | |
129 | if (is_write_device_private_entry(entry)) { | |
130 | pte_t newpte; | |
131 | ||
132 | /* | |
133 | * We do not preserve soft-dirtiness. See | |
134 | * copy_one_pte() for explanation. | |
135 | */ | |
136 | make_device_private_entry_read(&entry); | |
137 | newpte = swp_entry_to_pte(entry); | |
138 | set_pte_at(mm, addr, pte, newpte); | |
139 | ||
140 | pages++; | |
141 | } | |
1da177e4 LT |
142 | } |
143 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
6606c3e0 | 144 | arch_leave_lazy_mmu_mode(); |
705e87c0 | 145 | pte_unmap_unlock(pte - 1, ptl); |
7da4d641 PZ |
146 | |
147 | return pages; | |
1da177e4 LT |
148 | } |
149 | ||
7d12efae AM |
150 | static inline unsigned long change_pmd_range(struct vm_area_struct *vma, |
151 | pud_t *pud, unsigned long addr, unsigned long end, | |
152 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
1da177e4 LT |
153 | { |
154 | pmd_t *pmd; | |
a5338093 | 155 | struct mm_struct *mm = vma->vm_mm; |
1da177e4 | 156 | unsigned long next; |
7da4d641 | 157 | unsigned long pages = 0; |
72403b4a | 158 | unsigned long nr_huge_updates = 0; |
a5338093 | 159 | unsigned long mni_start = 0; |
1da177e4 LT |
160 | |
161 | pmd = pmd_offset(pud, addr); | |
162 | do { | |
25cbbef1 MG |
163 | unsigned long this_pages; |
164 | ||
1da177e4 | 165 | next = pmd_addr_end(addr, end); |
84c3fc4e | 166 | if (!is_swap_pmd(*pmd) && !pmd_trans_huge(*pmd) && !pmd_devmap(*pmd) |
5c7fb56e | 167 | && pmd_none_or_clear_bad(pmd)) |
88a9ab6e | 168 | continue; |
a5338093 RR |
169 | |
170 | /* invoke the mmu notifier if the pmd is populated */ | |
171 | if (!mni_start) { | |
172 | mni_start = addr; | |
173 | mmu_notifier_invalidate_range_start(mm, mni_start, end); | |
174 | } | |
175 | ||
84c3fc4e | 176 | if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { |
6b9116a6 | 177 | if (next - addr != HPAGE_PMD_SIZE) { |
fd60775a | 178 | __split_huge_pmd(vma, pmd, addr, false, NULL); |
6b9116a6 | 179 | } else { |
f123d74a | 180 | int nr_ptes = change_huge_pmd(vma, pmd, addr, |
e944fd67 | 181 | newprot, prot_numa); |
f123d74a MG |
182 | |
183 | if (nr_ptes) { | |
72403b4a MG |
184 | if (nr_ptes == HPAGE_PMD_NR) { |
185 | pages += HPAGE_PMD_NR; | |
186 | nr_huge_updates++; | |
187 | } | |
1ad9f620 MG |
188 | |
189 | /* huge pmd was handled */ | |
f123d74a MG |
190 | continue; |
191 | } | |
7da4d641 | 192 | } |
88a9ab6e | 193 | /* fall through, the trans huge pmd just split */ |
cd7548ab | 194 | } |
25cbbef1 | 195 | this_pages = change_pte_range(vma, pmd, addr, next, newprot, |
0f19c179 | 196 | dirty_accountable, prot_numa); |
25cbbef1 | 197 | pages += this_pages; |
1da177e4 | 198 | } while (pmd++, addr = next, addr != end); |
7da4d641 | 199 | |
a5338093 RR |
200 | if (mni_start) |
201 | mmu_notifier_invalidate_range_end(mm, mni_start, end); | |
202 | ||
72403b4a MG |
203 | if (nr_huge_updates) |
204 | count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates); | |
7da4d641 | 205 | return pages; |
1da177e4 LT |
206 | } |
207 | ||
7d12efae | 208 | static inline unsigned long change_pud_range(struct vm_area_struct *vma, |
c2febafc | 209 | p4d_t *p4d, unsigned long addr, unsigned long end, |
7d12efae | 210 | pgprot_t newprot, int dirty_accountable, int prot_numa) |
1da177e4 LT |
211 | { |
212 | pud_t *pud; | |
213 | unsigned long next; | |
7da4d641 | 214 | unsigned long pages = 0; |
1da177e4 | 215 | |
c2febafc | 216 | pud = pud_offset(p4d, addr); |
1da177e4 LT |
217 | do { |
218 | next = pud_addr_end(addr, end); | |
219 | if (pud_none_or_clear_bad(pud)) | |
220 | continue; | |
7da4d641 | 221 | pages += change_pmd_range(vma, pud, addr, next, newprot, |
4b10e7d5 | 222 | dirty_accountable, prot_numa); |
1da177e4 | 223 | } while (pud++, addr = next, addr != end); |
7da4d641 PZ |
224 | |
225 | return pages; | |
1da177e4 LT |
226 | } |
227 | ||
c2febafc KS |
228 | static inline unsigned long change_p4d_range(struct vm_area_struct *vma, |
229 | pgd_t *pgd, unsigned long addr, unsigned long end, | |
230 | pgprot_t newprot, int dirty_accountable, int prot_numa) | |
231 | { | |
232 | p4d_t *p4d; | |
233 | unsigned long next; | |
234 | unsigned long pages = 0; | |
235 | ||
236 | p4d = p4d_offset(pgd, addr); | |
237 | do { | |
238 | next = p4d_addr_end(addr, end); | |
239 | if (p4d_none_or_clear_bad(p4d)) | |
240 | continue; | |
241 | pages += change_pud_range(vma, p4d, addr, next, newprot, | |
242 | dirty_accountable, prot_numa); | |
243 | } while (p4d++, addr = next, addr != end); | |
244 | ||
245 | return pages; | |
246 | } | |
247 | ||
7da4d641 | 248 | static unsigned long change_protection_range(struct vm_area_struct *vma, |
c1e6098b | 249 | unsigned long addr, unsigned long end, pgprot_t newprot, |
4b10e7d5 | 250 | int dirty_accountable, int prot_numa) |
1da177e4 LT |
251 | { |
252 | struct mm_struct *mm = vma->vm_mm; | |
253 | pgd_t *pgd; | |
254 | unsigned long next; | |
255 | unsigned long start = addr; | |
7da4d641 | 256 | unsigned long pages = 0; |
1da177e4 LT |
257 | |
258 | BUG_ON(addr >= end); | |
259 | pgd = pgd_offset(mm, addr); | |
260 | flush_cache_range(vma, addr, end); | |
16af97dc | 261 | inc_tlb_flush_pending(mm); |
1da177e4 LT |
262 | do { |
263 | next = pgd_addr_end(addr, end); | |
264 | if (pgd_none_or_clear_bad(pgd)) | |
265 | continue; | |
c2febafc | 266 | pages += change_p4d_range(vma, pgd, addr, next, newprot, |
4b10e7d5 | 267 | dirty_accountable, prot_numa); |
1da177e4 | 268 | } while (pgd++, addr = next, addr != end); |
7da4d641 | 269 | |
1233d588 IM |
270 | /* Only flush the TLB if we actually modified any entries: */ |
271 | if (pages) | |
272 | flush_tlb_range(vma, start, end); | |
16af97dc | 273 | dec_tlb_flush_pending(mm); |
7da4d641 PZ |
274 | |
275 | return pages; | |
276 | } | |
277 | ||
278 | unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, | |
279 | unsigned long end, pgprot_t newprot, | |
4b10e7d5 | 280 | int dirty_accountable, int prot_numa) |
7da4d641 | 281 | { |
7da4d641 PZ |
282 | unsigned long pages; |
283 | ||
7da4d641 PZ |
284 | if (is_vm_hugetlb_page(vma)) |
285 | pages = hugetlb_change_protection(vma, start, end, newprot); | |
286 | else | |
4b10e7d5 | 287 | pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); |
7da4d641 PZ |
288 | |
289 | return pages; | |
1da177e4 LT |
290 | } |
291 | ||
b6a2fea3 | 292 | int |
1da177e4 LT |
293 | mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, |
294 | unsigned long start, unsigned long end, unsigned long newflags) | |
295 | { | |
296 | struct mm_struct *mm = vma->vm_mm; | |
297 | unsigned long oldflags = vma->vm_flags; | |
298 | long nrpages = (end - start) >> PAGE_SHIFT; | |
299 | unsigned long charged = 0; | |
1da177e4 LT |
300 | pgoff_t pgoff; |
301 | int error; | |
c1e6098b | 302 | int dirty_accountable = 0; |
1da177e4 LT |
303 | |
304 | if (newflags == oldflags) { | |
305 | *pprev = vma; | |
306 | return 0; | |
307 | } | |
308 | ||
309 | /* | |
310 | * If we make a private mapping writable we increase our commit; | |
311 | * but (without finer accounting) cannot reduce our commit if we | |
5a6fe125 MG |
312 | * make it unwritable again. hugetlb mapping were accounted for |
313 | * even if read-only so there is no need to account for them here | |
1da177e4 LT |
314 | */ |
315 | if (newflags & VM_WRITE) { | |
84638335 KK |
316 | /* Check space limits when area turns into data. */ |
317 | if (!may_expand_vm(mm, newflags, nrpages) && | |
318 | may_expand_vm(mm, oldflags, nrpages)) | |
319 | return -ENOMEM; | |
5a6fe125 | 320 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_HUGETLB| |
cdfd4325 | 321 | VM_SHARED|VM_NORESERVE))) { |
1da177e4 | 322 | charged = nrpages; |
191c5424 | 323 | if (security_vm_enough_memory_mm(mm, charged)) |
1da177e4 LT |
324 | return -ENOMEM; |
325 | newflags |= VM_ACCOUNT; | |
326 | } | |
327 | } | |
328 | ||
1da177e4 LT |
329 | /* |
330 | * First try to merge with previous and/or next vma. | |
331 | */ | |
332 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); | |
333 | *pprev = vma_merge(mm, *pprev, start, end, newflags, | |
19a809af AA |
334 | vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), |
335 | vma->vm_userfaultfd_ctx); | |
1da177e4 LT |
336 | if (*pprev) { |
337 | vma = *pprev; | |
e86f15ee | 338 | VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); |
1da177e4 LT |
339 | goto success; |
340 | } | |
341 | ||
342 | *pprev = vma; | |
343 | ||
344 | if (start != vma->vm_start) { | |
345 | error = split_vma(mm, vma, start, 1); | |
346 | if (error) | |
347 | goto fail; | |
348 | } | |
349 | ||
350 | if (end != vma->vm_end) { | |
351 | error = split_vma(mm, vma, end, 0); | |
352 | if (error) | |
353 | goto fail; | |
354 | } | |
355 | ||
356 | success: | |
357 | /* | |
358 | * vm_flags and vm_page_prot are protected by the mmap_sem | |
359 | * held in write mode. | |
360 | */ | |
361 | vma->vm_flags = newflags; | |
6d2329f8 | 362 | dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); |
64e45507 | 363 | vma_set_page_prot(vma); |
d08b3851 | 364 | |
7d12efae AM |
365 | change_protection(vma, start, end, vma->vm_page_prot, |
366 | dirty_accountable, 0); | |
7da4d641 | 367 | |
36f88188 KS |
368 | /* |
369 | * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major | |
370 | * fault on access. | |
371 | */ | |
372 | if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && | |
373 | (newflags & VM_WRITE)) { | |
374 | populate_vma_page_range(vma, start, end, NULL); | |
375 | } | |
376 | ||
84638335 KK |
377 | vm_stat_account(mm, oldflags, -nrpages); |
378 | vm_stat_account(mm, newflags, nrpages); | |
63bfd738 | 379 | perf_event_mmap(vma); |
1da177e4 LT |
380 | return 0; |
381 | ||
382 | fail: | |
383 | vm_unacct_memory(charged); | |
384 | return error; | |
385 | } | |
386 | ||
7d06d9c9 DH |
387 | /* |
388 | * pkey==-1 when doing a legacy mprotect() | |
389 | */ | |
390 | static int do_mprotect_pkey(unsigned long start, size_t len, | |
391 | unsigned long prot, int pkey) | |
1da177e4 | 392 | { |
62b5f7d0 | 393 | unsigned long nstart, end, tmp, reqprot; |
1da177e4 LT |
394 | struct vm_area_struct *vma, *prev; |
395 | int error = -EINVAL; | |
396 | const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); | |
f138556d PK |
397 | const bool rier = (current->personality & READ_IMPLIES_EXEC) && |
398 | (prot & PROT_READ); | |
399 | ||
1da177e4 LT |
400 | prot &= ~(PROT_GROWSDOWN|PROT_GROWSUP); |
401 | if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */ | |
402 | return -EINVAL; | |
403 | ||
404 | if (start & ~PAGE_MASK) | |
405 | return -EINVAL; | |
406 | if (!len) | |
407 | return 0; | |
408 | len = PAGE_ALIGN(len); | |
409 | end = start + len; | |
410 | if (end <= start) | |
411 | return -ENOMEM; | |
b845f313 | 412 | if (!arch_validate_prot(prot)) |
1da177e4 LT |
413 | return -EINVAL; |
414 | ||
415 | reqprot = prot; | |
1da177e4 | 416 | |
dc0ef0df MH |
417 | if (down_write_killable(¤t->mm->mmap_sem)) |
418 | return -EINTR; | |
1da177e4 | 419 | |
e8c24d3a DH |
420 | /* |
421 | * If userspace did not allocate the pkey, do not let | |
422 | * them use it here. | |
423 | */ | |
424 | error = -EINVAL; | |
425 | if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) | |
426 | goto out; | |
427 | ||
097d5910 | 428 | vma = find_vma(current->mm, start); |
1da177e4 LT |
429 | error = -ENOMEM; |
430 | if (!vma) | |
431 | goto out; | |
097d5910 | 432 | prev = vma->vm_prev; |
1da177e4 LT |
433 | if (unlikely(grows & PROT_GROWSDOWN)) { |
434 | if (vma->vm_start >= end) | |
435 | goto out; | |
436 | start = vma->vm_start; | |
437 | error = -EINVAL; | |
438 | if (!(vma->vm_flags & VM_GROWSDOWN)) | |
439 | goto out; | |
7d12efae | 440 | } else { |
1da177e4 LT |
441 | if (vma->vm_start > start) |
442 | goto out; | |
443 | if (unlikely(grows & PROT_GROWSUP)) { | |
444 | end = vma->vm_end; | |
445 | error = -EINVAL; | |
446 | if (!(vma->vm_flags & VM_GROWSUP)) | |
447 | goto out; | |
448 | } | |
449 | } | |
450 | if (start > vma->vm_start) | |
451 | prev = vma; | |
452 | ||
453 | for (nstart = start ; ; ) { | |
a8502b67 | 454 | unsigned long mask_off_old_flags; |
1da177e4 | 455 | unsigned long newflags; |
7d06d9c9 | 456 | int new_vma_pkey; |
1da177e4 | 457 | |
7d12efae | 458 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
1da177e4 | 459 | |
f138556d PK |
460 | /* Does the application expect PROT_READ to imply PROT_EXEC */ |
461 | if (rier && (vma->vm_flags & VM_MAYEXEC)) | |
462 | prot |= PROT_EXEC; | |
463 | ||
a8502b67 DH |
464 | /* |
465 | * Each mprotect() call explicitly passes r/w/x permissions. | |
466 | * If a permission is not passed to mprotect(), it must be | |
467 | * cleared from the VMA. | |
468 | */ | |
469 | mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | | |
470 | ARCH_VM_PKEY_FLAGS; | |
471 | ||
7d06d9c9 DH |
472 | new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); |
473 | newflags = calc_vm_prot_bits(prot, new_vma_pkey); | |
a8502b67 | 474 | newflags |= (vma->vm_flags & ~mask_off_old_flags); |
1da177e4 | 475 | |
7e2cff42 PBG |
476 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |
477 | if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { | |
1da177e4 LT |
478 | error = -EACCES; |
479 | goto out; | |
480 | } | |
481 | ||
482 | error = security_file_mprotect(vma, reqprot, prot); | |
483 | if (error) | |
484 | goto out; | |
485 | ||
486 | tmp = vma->vm_end; | |
487 | if (tmp > end) | |
488 | tmp = end; | |
489 | error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); | |
490 | if (error) | |
491 | goto out; | |
492 | nstart = tmp; | |
493 | ||
494 | if (nstart < prev->vm_end) | |
495 | nstart = prev->vm_end; | |
496 | if (nstart >= end) | |
497 | goto out; | |
498 | ||
499 | vma = prev->vm_next; | |
500 | if (!vma || vma->vm_start != nstart) { | |
501 | error = -ENOMEM; | |
502 | goto out; | |
503 | } | |
f138556d | 504 | prot = reqprot; |
1da177e4 LT |
505 | } |
506 | out: | |
507 | up_write(¤t->mm->mmap_sem); | |
508 | return error; | |
509 | } | |
7d06d9c9 DH |
510 | |
511 | SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, | |
512 | unsigned long, prot) | |
513 | { | |
514 | return do_mprotect_pkey(start, len, prot, -1); | |
515 | } | |
516 | ||
c7142aea HC |
517 | #ifdef CONFIG_ARCH_HAS_PKEYS |
518 | ||
7d06d9c9 DH |
519 | SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, |
520 | unsigned long, prot, int, pkey) | |
521 | { | |
522 | return do_mprotect_pkey(start, len, prot, pkey); | |
523 | } | |
e8c24d3a DH |
524 | |
525 | SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) | |
526 | { | |
527 | int pkey; | |
528 | int ret; | |
529 | ||
530 | /* No flags supported yet. */ | |
531 | if (flags) | |
532 | return -EINVAL; | |
533 | /* check for unsupported init values */ | |
534 | if (init_val & ~PKEY_ACCESS_MASK) | |
535 | return -EINVAL; | |
536 | ||
537 | down_write(¤t->mm->mmap_sem); | |
538 | pkey = mm_pkey_alloc(current->mm); | |
539 | ||
540 | ret = -ENOSPC; | |
541 | if (pkey == -1) | |
542 | goto out; | |
543 | ||
544 | ret = arch_set_user_pkey_access(current, pkey, init_val); | |
545 | if (ret) { | |
546 | mm_pkey_free(current->mm, pkey); | |
547 | goto out; | |
548 | } | |
549 | ret = pkey; | |
550 | out: | |
551 | up_write(¤t->mm->mmap_sem); | |
552 | return ret; | |
553 | } | |
554 | ||
555 | SYSCALL_DEFINE1(pkey_free, int, pkey) | |
556 | { | |
557 | int ret; | |
558 | ||
559 | down_write(¤t->mm->mmap_sem); | |
560 | ret = mm_pkey_free(current->mm, pkey); | |
561 | up_write(¤t->mm->mmap_sem); | |
562 | ||
563 | /* | |
564 | * We could provie warnings or errors if any VMA still | |
565 | * has the pkey set here. | |
566 | */ | |
567 | return ret; | |
568 | } | |
c7142aea HC |
569 | |
570 | #endif /* CONFIG_ARCH_HAS_PKEYS */ |